If you're a diaper-sewing WAHM ... how did you come up with your sewing pattern?

My understanding is that copyright law does not mean that, for instance, Super Diaper Company can't sell diapers made from the Kwik Sew pattern ... they just can't say "These are Kwik Sew" (trademark violation) and they can't sell "Super Diaper Company sewing pattern" (which is Kwik Sew's pattern with a new name).

I say this NOT because I intend to or endorse using someone else's pattern. I'm just putting it out there so nobody is afraid to admit, or nobody gets flamed for saying, I used so-and-sos pattern for my WAHM business.